Airborne Avian Influenza Virus in Ambient Air in the Winter Habitats of Migratory Birds

Abstract

Outbreaks of avian influenza virus (AIV) have raised public concerns recently. Airborne AIV has been evaluated in live poultry markets and case farms; however, no study has discussed airborne AIV in ambient air in the winter habitats of migratory birds. Therefore, this study aimed to evaluate airborne AIV, specifically H5, H7, and H9, in a critical winter habitat of migratory birds and assess the factors influencing airborne AIV transmission in ambient air to provide novel insights into the epidemiology of avian influenza. A total of 357 ambient air samples were collected in the Aogu Wetland, Taiwan, Republic of China, between October 2017 and December 2019 and analyzed using quantitative real-time polymerase chain reaction. The effects of environmental factors including air pollutants, meteorological factors, and the species of the observed migratory birds on the concentration of airborne AIV were also analyzed. To our knowledge, this is the first study to investigate the relationship between airborne AIV in ambient air and the influence factors in the winter habitats of migratory birds, demonstrating the benefits of environmental sampling for infectious disease epidemiology. The positive rate of airborne H7 (12%) was higher than that of H5 (8%) and H9 (10%). The daily mean temperature and daily maximum temperature had a significant negative correlation with influenza A, H7, and H9. Cold air masses and bird migration were significantly associated with airborne H9 and H7, respectively. In addition, we observed a significant correlation between AIV and the number of pintails, common teals, Indian spot-billed ducks, northern shovelers, Eurasian wigeons, tufted ducks, pied avocets, black-faced spoonbills, and great cormorants. In conclusion, we demonstrated the potential for alternative surveillance approaches (monitoring bird species) as an indicator for influenza-related risks and identified cold air masses and the presence of specific bird species as potential drivers of the presence and/or the airborne concentration of AIV.

Airborne Influenza Virus in Daycare Centers

“…Air samplers were set up at a height of 1 m because this height was near the children’s breathing zone. Airborne influenza viruses were collected on 1.0 μm-pore polytetrafluoroethylene (Teflon; Pall Corporation, New York, NY, USA) membrane filters in disposable plastic cassettes at a sampling rate of 20 L/min for a 6-h sampling period (37 mm; HIBLOW SPP-25 GA, Techno Takatsuki, Osaka, Japan) [ 29 , 30 , 31 ]. The collected air samples were then transported at 4 °C to our laboratory and isolated within 3 days of collection.…”

“…Samplers: National Institute for Occupational Safety and Health (NIOSH) bioaerosol sampler (BC251) with SKC AirChek XR5000 pump (SKC, Eighty Four, PA, USA) Sampling rates and time: 3.5 L/min for 30 min, and 6-13 air samplers per week. Sampling periods: October 2016 to June 2018 except during the summer holidays in 2017 (weeks [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] Children who attend daycare centers are exposed to higher levels of infectious agents and air pollutants-including carbon monoxide (CO), carbon dioxide (CO 2 ), and ultrafine particles (UFPs)-than those who are cared for at home [12,13]. Studies have reported that children exposed to UFPs (aerodynamic diameter < 0.1 µm) have an increased risk of respiratory infection and hospital admission [14,15], and the amount of influenza virus found in the fraction of UFP S less than 0.25 um was 15% [16].…”

Continuous surveillance of pathogens detects excretion of avian orthoreovirus and parvovirus by several wild waterfowl: possible wild bird reservoirs

“…Consequently, wild birds are of paramount importance in the propagation of the pathogens. Specifically, migratory wild birds frequently traverse national and even intercontinental boundaries during migration or flight, serving as vectors for long-distance transmission of pathogenic viruses, bacteria, and parasites ( Envelope et al, 2021 ; Zhang et al, 2022 ). Furthermore, these pathogens undergo genetic evolution and reassortment mutations, leading to the emergence of mutated strains with altered pathogenicity and antigenicity.…”

The role of airborne particles in the epidemiology of clade 2.3.4.4b H5N1 high pathogenicity avian influenza virus in commercial poultry production units

“…faecal-oral route) (12,13,17,18). However, transmission via airborne particles may be relevant for some strains of AIV (e.g., H9N2) (13,14,(19)(20)(21)(22)(23)(24)(25).…”

“…Airborne transmission over short distances between birds has been demonstrated for some AIV strains (13,14,(19)(20)(21)(22)(23)(24)(25), and AIV has been detected in the air around wild birds in their natural habitat (14). However, in the context of the GsGD lineage of viruses, H5Nx HPAIV airborne transmission among avian species has not been conclusively demonstrated.…”